O-ring construction



D. LITTMANN Jan. 30, 1968 O-RING CONSTRUCTION Filed Dec. 2, 1966 Unite States ABSTRACT OF THE DISCLOSURE A stethoscope head with at least one metal microphone having means for preventing the cold metal of the microphone from chilling a patient. The means illustrated comprises a rubber-like annular, generally U- shaped cross section cover for the periphery of the mi crophone.

The present invention relates to a metallic stethoscope and more particularly to an improvement in a medical stethoscope which enhances comfort when the stethoscope is applied to the human body.

Medical stethoscope heads are conventionally made of metal materials since metals are extremely durable, give good sound reproduction and can be machined into precise microphone shapes. The bare metal of such stethoscopes, however, can chill and thereby be uncomfortable when pressed against ones body. This problem is particularly disturbing with respect to pediatric stethoscopes where young children are frequently upset by the cold sensation of a probing metallic stethoscope head.

It has been found that insulating materials, such as rubber, are not chilling when applied to the skin and, consequently, there have been a number of constructions utilizing rubber coverings for stethoscopes, such, for example, as the construction illustrated in United States Letters Patent No. 3,215,224. While these earlier constructions have proved to be useful and to some extent satisfactory, they nonetheless are susceptible to further improvements. Thus, it is an object of the present invention to provide a stethoscope having a nonmetallic nonchilling, contacting surface which is easy to manufacture, simple to maintain, capable of considerable abuse without damage, noninterfering with proper sound transmission, and is attractive in appearance.

It is also an object of the present invention to provide a stethoscope having a nonchilling covering material for a stethoscope microphone which is adapted to minimize sound leakage between the microphone and the individuals body by at least partially conforming to a patients body. The covering material also enlarges the bell-shaped sound collecting component of the stethoscope head without interfering with sound transmission.

In the present invention there is provided a stethoscope head having a metal microphone with a continuous peripheral rim lying in a plane spaced outwardly of the cent-er aperture. A resilient nonmetallic annular casing having a U-shaped cross section through the annular shape is positioned, with one side Wall forming one leg of the U-shape on one side and the other side wall forming the outer leg of the U-shape on the other side of the microphone rim. The interconnecting portion of the U- shape which comprises a relatively large cross sectional area is positioned directly at the edge of the rim. The resilient nonmetallic annular member thereby provides an outwardly extending lip which covers the rim and provides a resilient nonmetallic nonchilling mass for direct and conforming contact with the body of a patient.

These and other objects, features and advantages of the present invention will be better understood and appreciated from the following detailed description read in conjunction with the accompanying drawings in which:

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FIG. 1 is a cross sectional view taken through the axis of the stethoscope head showing the improvement of this invention; and

FIG. 2 is a plan view looking from the right of FIG. 1.

With reference now to the drawings, the metallic stethoscope head 10 is shown with a conventional diaphragm microphone 17 in back to back relation with a bell shaped open microphone 18 separated by an intermediate body portion 11. The diaphragm and retaining ring covering microphone 17 are conventional and are not shown. At the apex of each microphone are aligned apertures 16 and 12, extending perpendicular to a bore which snugly receives a conventional tubular stem 14, which in turn is conventionally adapted to rotate within the bore to interconnect either of microphones 17 or 18 upon proper rotation with a conventional binaural. The stem 14 is adapted to be connected to the stem of a conventional Y-tube of any well known binaural, such, for example, as described in United States Letters Patent 3,108,652, issued October 29, 1963.

The specific stethoscope head construction may vary greatly in accordance with known practice and in some cases a single bell shaped microphone such as 18, may be used in the practice of the invention rather than a dual microphone head.

The bell microphone 18 has a continuous peripheral rim 25, the outer edge of which lies in a plane spaced outwardly from the central aperture 16. This rim is continuous with an outer annular wall 22 which lies in planes at about a 45 angle to the axis of aperture 16. The inner wall 21 of microphone 18 is hell shaped with its outer extremities approaching a parallel relationship with the wall 22. The extreme outer edge of the microphone 18 is narrow in diameter being tapered from a wider base, and is curved as illustrated.

A covering 30 covers the rim 25 and consists of an annular flexible nonmetallic member. Preferably, this covering is formed of a neoprene or other synthetic rubber material which may be stretched or distorted to be snapped over the rim 25. The covering 30 is formed with opposed side walls 31 and 32. with side wall 31 slightly longer than the inner side wall 32. The side walls 31 and 32 are interconnected by relatively large mass 33 which is integral with side walls 31 and 32 forming a cover having a U-shaped cross section as illustrated. The side walls 31 and 32 are substantially uniform in thickness from their free end to the end integral with the mass 33. The free edges of Walls 31 and 32 are preferably feathered or curved. The mass 33 has a length (as measured along an axis parallel to and bisecting legs 31 and 32) which is substantially greater than the thickness of either sidewall 31 or sidewall 32.

As illustrated in FIG. 1, the covering material effectively extends the diameter of the bell microphone 18 and additionally provides a resilient continuous edge adapted to 'be deformed to conform with the body of a patient against whom it is pressed. The deformation however is a continuous and gentle one so that the overall shape of the bell microphone 18 is not significantly changed while at the same time leakage from under the edge of the microphone 18 is effectively eliminated.

What is claimed is:

1. In a stethoscope head construction having a metal microphone with said microphone having a continuous peripheral rim lying substantially in a plane, said rim being spaced outwardly of a central aperture defined by said microphone and with said rim being defined by inner and outer annular sidewalls of said microphone, the improvement comprising,

said outer sidewall lying in planes at 45 angles to the axis of said central aperture and said inner sidewall being flared outwardly towards said outer sidewall whereby said microphone is formed with an annular body which is tapered in cross section,

an integral resilient, insulating, deformable covering defining a generally U-shaped cross section, having homogeneous inner and outer annular walls and an annular mass with said outer Wall being longer than said inner wall,

said inner and outer Walls lying respectively in facing relation against said inner and outer sidewalls to support said covering and said mass lying against said rim, said mass extending outwardly from said rim and continuous therewith to form an outwardly flared continuous extension of said sidewalls with said extension being of substantially the same thickness as said sidewall rim, and with said mass extending outwardly a distance greater than the thickness of said inner wall.

2. A stethoscope as set forth in claim 1 wherein said inner Wall lies in planes which are substantially at a 45 angle to the axis of said central aperture.

References Cited UNITED STATES PATENTS 1,254,629 1/1918 Miller 179--l82 1,708,398 4/1929 Pilling 181-24 1,832,422 11/1931 Filling 18124 STEPHEN J. TOMSKY, Primary Examiner. 

